Patients with brain disorder, such as cerebral apoplexy, and elderly people often have reduced swallowing function and suffer from dysphagia, in which at the time of ingesting a food, the food accidentally flows into the trachea or lung. As a method for feeding to such a dysphagic patient, a tube feeding method, in which a liquid food is administered directly into the stomach through a tube, is known. In the tube feeding method, it is important to suppress gastroesophageal reflux, which is the flow of the liquid food administered into the stomach back to the esophagus.
Conventionally, as a method for suppressing gastroesophageal reflux, a method in which a semisolid liquid food prepared by incorporating a pre-thickened thickener is administered is known (see, e.g., Patent Document 1). However, semisolid liquid foods are disadvantageous in that administration into the stomach through a tube is difficult to be made. Then, as a technique of compensating with such a disadvantage of semisolid liquid foods, a method in which a solution containing a thickener is administered through a tube before and after the tube administration of a liquid food, thereby causing the gelation of the liquid food injected into the stomach to suppress gastroesophageal reflux, has been reported (see, e.g., Patent Document 2). However, according to the technique of Patent Document 2, the administration of the solution containing a thickener is necessary in addition to the administration of liquid food, and thus there is an increased burden on the care worker. The technique also has a problem in that if, by any change, the administration of the solution containing a thickener is forgotten, gastroesophageal reflux cannot be suppressed.
Then, in recent years, as a liquid food that is fluid when ingested or administered through a tube, but turns into a semisolid upon arrival in the stomach, an emulsified food composition containing a protein, a lipid, a carbohydrate, and a thickener has been proposed (see, e.g., Patent Document 3). However, the emulsified food composition described in Patent Document 3 is disadvantageous in that when it is subjected to heat sterilization, etc., gelation occurs, resulting in loss of fluidity, and also aggregates are formed or layer separation occurs, making it impossible to maintain an good emulsified state. A food composition that cannot be heat-sterilized is also difficult to distribute or store at normal temperature. Therefore, the emulsified food composition described in Patent Document 3 has a problem in practical use that has not yet been solved.
Against this background, there has a demand for the development of an emulsified food composition which has good fluidity and emulsification stability even when subjected to a heat sterilization treatment, and which also gels upon entering into the stomach, whereby gastroesophageal reflux can be prevented.